Series electron

J. B. Price, in H. R. Huff and R. R. Burgess, eds.. Semiconductor Silicon, The Electrochemical Society Proceedings Series, Electronics/Electrothermics and Metallurgy Division, Electrochemical Society, New York, 1973. 

Vanadium [7440-62-2] V, (at. no. 23, at. wt 50.942) is a member of Group 5 (VB) of the Periodic Table. It is a gray body-centered-cubic metal in the first transition series (electronic configuration When highly pure, it is very soft and dutile. Because of its high melting point, vanadium is referred to as a... 

Douglas, A. S., Proc. Cambridge Phil. Soc. 52, 687, "A method for improving energy-level calculations for series electrons." Inclusion of a polarization potential in the Hartree-Slater-Fock equation. 

TOMES. 1994. TOMES (Toxicology, Occupational Medicine and Environmental Series) electronic database. Endrin Endrin metabolites. Micromedex, Inc. Vol. 78. 

Mulliken, who published the first articles in his series, "Electronic Structures of Molecules and Valence," in Physical Review, was not keen initially on the new journal but nonetheless shifted his series to the Journal of... 

Like the 1994-issue of the series "Electron Transfer", the second volume again covers various aspects of this fundamental process. The articles are concerned with the experimental and theoretical aspects of electron transfer in chemistry and biology. In the latter, emphasis is given to energy transfer, which is also part of photosynthesis. 

The possible states of electrons are called orbitals. These are indicated by what is known as the principal quantum number and by a letter—s, p, or d. The orbitals are filled one by one as the number of electrons increases. Each orbital can hold a maximum of two electrons, which must have oppositely directed spins. Fig. A shows the distribution of the electrons among the orbitals for each of the elements. For example, the six electrons of carbon (B1) occupy the Is orbital, the 2s orbital, and two 2p orbitals. A filled Is orbital has the same electron configuration as the noble gas helium (He). This region of the electron shell of carbon is therefore abbreviated as He in Fig. A. Below this, the numbers of electrons in each of the other filled orbitals (2s and 2p in the case of carbon) are shown on the right margin. For example, the electron shell of chlorine (B2) consists of that of neon (Ne) and seven additional electrons in 3s and 3p orbitals. In iron (B3), a transition metal of the first series, electrons occupy the 4s orbital even though the 3d orbitals are still partly empty. Many reactions of the transition metals involve empty d orbitals—e.g., redox reactions or the formation of complexes with bases. 

Symbol Fm atomic number 100 atomic weight 257 a man-made transuranium radioactive element of the actinide series electron configuration [Rn]5/i27s2 oxidation state -1-3 sixteen isotopes are known most stable isotope Fm-257, ti/2 100.5 days. 

Symbol La atomic number 57 atomic weight 138.91 a rare-earth transition metal, precursor to a series of 14 inner-transition elements known as the lanthanide series electron configuration [XejSdiGs oxidation state -i-3 atomic radius 1.879A ionic radius (LaS+) 1.061A electronegativity 1.17 two natural isotopes are La-139 (99.911%) and La-138 (0.089%). 

Symbol Md atomic number 101 atomic weight (most stable isotope) 257 a man-made radioactive transuranium element an inner-transition element of actinide series electron configuration [Rn]5/i37s2 valence +2, -i-3. Isotopes, half-lives and their decay modes are ... 

Symbol Np atomic number 93 atomic weight 237 (most stable isotope) a man-made transuranium radioactive element actinide series electron configuration [Rn]5/" 6di7s2 oxidation states +3, +4, -i-5 and +6 most stable valence... 

Thus, the pKa values of an acid is only determined by its rate of dissociation [reaction (1)]. Hence, in a homologous series, electron-withdrawing substituents reduce the pKa value by rendering the environment of the acidic function more positive and thereby accelerating the rate of dissociation of the (positively charged) proton. In contrast, an electron-donating substituent increases the pKa value. 

In order to lower the proximity effects caused by the solvent, C chemical shift values of compounds 75 and 76 have also been collected in CDCI3 solutions (Table 40). In the compound 75 series, electron-withdrawing and -repelling substituents cause shielding and deshielding of C-3 (ASCS 3.27 ppm), respectively, while the usual inverted effect can be evidenced for C-2 (ASCS 2.74 ppm). 

Early in the actinide series, electrons in the 6d orbitals are lower in energy than there is 5f orbitals, This is clear from the ground-state electronic configurations (Table 9.3) of the atoms, which show that the 6d orbitals are filled before 5f. The 5f orbitals are starting to be filled at protoactinium, and with the exception of curium, the fid orbitals are not occupied again. 

The issue of the wire-like properties of arrays of metal complexes has been of some interest, has been reviewed recently. i See Volume 5 of the series Electron Transfer in Chemistry... 

Needless to say, electron transfer not only plays a crucial role in excited state systems but also in organic,organo-metallic, biochemical and heterogeneous systems as well as in new materials. Therefore the new general series. Electron Transfer, has been designed to provide the reader with up-to-date chapters by leading scientists who have already contributed in terms of a long-term research to the topic of their own articles. 

By convention, the electrode potential of any half-reaction is expressed relative to that of a standard hydrogen electrode (half-reaction 2H+ -p 2e -H2) and is called the standard electrode potential, E . Table 34.1 shows the values of E" for selected half-reactions. With any pair of half-reactions from this series, electrons will flow from that having the lowest electrode potential to that of the highest. " is determined at pH = 0. It is often more appropriate to express standard electrode potentials at pH 7 for biological systems, and the symbol is used in all circumstances, it is important that the pH is clearly stated. 

The seventh period of the periodic table is occupied by a similar series called the actinide series. Beginning with actinium the 5/ electron shell is populated in a matmer analogous to filling the 4/ electron shell in the lanthanide series. A suggested electronic configuration [K2, M6], is shown in Table 9.2. After the alkaline earth radium, additional electrons are added to the 6d and 5/ shells, beginning the actinide series. At the beginning of the actinide series electrons are added... 

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